I agree on the spindle depth below the mounting collar being at least 1". You could also set it close to the extension of the Sense Probe mounting bracket. Once I install the spindle, I will provide an update to this thread.
I haven't yet worked with this, as I go through a transition from a Shark Pro to our new HD4, so I may change my mind on this.
The HD4 comes with a Sense Probe. This device is used to determine the edges of your material and the center of that material - should you desire to use this method. It is held in that bracket using a magnet. After you perform this step, I would remove the Sense Probe from the mount so there is no opportunity for it banging around while you run the job(s). It may not interfere, but at face value, this is what I plan on doing.
There is a Sense Probe manual available from the NWA web site -
http://www.nextwaveautomation.com/downl ... l_1609.pdf. While the name of the manual is 'Sense Probe', the text of the manual uses the phrase 'Touch Probe'. I suspect that will be updated at some point.
To be clear for other Shark users, the Sense Probe is not the 'digitizer' (original phrase) or 'Digital Duplicator' (current phrase). The Sense Probe is only used to determine the edges and center of the material.